The invention relates in general to mechanical drive systems and in particular to mechanical drive systems for rotating turrets.
U.S. Pat. No. 6,101,917 issued to Klatte et al. on Aug. 15, 2000 discloses a mechanical assist turret drive system comprised of a turret drive assembly that rotates inside of an internal tooth fixed ring gear. The turret drive assembly is driven manually via an aiming wheel, input shaft, bevel gear mesh, shafted sprockets driven by a chain and an output gear that meshes with the internal tooth fixed ring gear. The system also provides means to disengage the drive system if the user decides to rotate the turret by hand.
However, because of the large amount of friction, manually rotating the turret by hand when the drive system is disengaged may be difficult or impossible, especially for those with lesser strength. In addition, the disengage components may not ensure a precise and consistent center distance in the gear mesh, which contributes to excessive backlash. Also, the use of a large number of drive components causes unnecessary friction and backlash. The drive system only provides single tooth to tooth contact in the pinion and ring gear mesh.
A need exists for a drive system that is less complex, has a fewer number of components, and has less backlash and friction than known systems.